code: def _sym_solve(Dinv, M, A, r1, r2, solve, splu=False):
      """
      An implementation of [4] equation 8.31 and 8.32
  
      References
      ----------
      .. [4] Andersen, Erling D., and Knud D. Andersen. "The MOSEK interior point
             optimizer for linear programming: an implementation of the
             homogeneous algorithm." High performance optimization. Springer US,
             2000. 197-232.
  
      """
      # [4] 8.31
      r = r2 + A.dot(Dinv * r1)
      if splu:
          v = solve(r)
      else:
          v = solve(M, r)
      # [4] 8.32
      u = Dinv * (A.T.dot(v) - r1)
      return u, v
  
file_path: catboost/contrib/python/scipy/py2/scipy/optimize/_linprog_ip.py
imports: from __future__ import print_function, division, absolute_import
  import numpy
  import scipy
  import scipy.sparse
  from warnings import warn
  from scipy.linalg import LinAlgError
  from .optimize import OptimizeWarning, _check_unknown_options
label_desc: Use image node_id 3 for calling a global function with example usage: _sym_solve(Dinv, M, A, r1, r2, solve, splu) and returns: u,  v